MystiQ is a fairly new Qt5/C++ FFmpeg-based audio and video converter for Linux and Microsoft Windows. A macOS version will also be available in the future.
I want to note that while the application is referred to as "MystiQ Video Converter" on its website, it actually supports both audio and video files.
This FFmpeg GUI comes with an easy-to-use user interface intended to get things done without distracting the user. It supports all the popular audio and video formats supported by FFmpeg, and comes with many presets.
